Track lining

ABSTRACT

A track point is lined by laterally moving it beyond the desired position to take into consideration the springback of the track due to the track tension caused by the lateral movement.

United States Patent [56] References Cited UNITED STATES PATENTS 3,338,174 8/1967 Oville r. 104/8 3,371,6l9 3/1968 Stewart 104/8 Primary Examiner-Arthur L. La Point Assistant Examiner-Richard A. Bertsch Attorney-Kurt Kelman ABSTRACT: A track point is lined by laterally moving it. beyond the desired position to take into consideration the springback of the track due to the track tension caused by the lateral movement.

1 TRACK LINING BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to improvements in track lining. A

As is known, the inherent resiliency of the steel rails of railroad tracks causes such tracks to spring back a certain distance along the path extending transversely to the track after the track has been laterally moved along this path and released, due to the track tension caused by the lateral movement. Of course, if a misalignedtrack point is laterally moved the exact distance to the desired position, the springback of the track will again cause misalignment, which must be corrected in a subsequent lining operation or operations until the desired position of the track has been achieved. In track lining, it is somewhat difficult to predetermine theexact additional distance by which the track must be laterally moved to take into consideration its springback and thus to assure reasonably accurate lining.

It is the primary object of the present invention not only to make it possible to predetermine this additional lateral moving distance fairly accurately but also to do this rapidly, simply and with relatively few, simple and sturdy structural elements which automatically adjust the lateral moving distance.

With this object in mind, accurate lining may be effected continuously at successive track lining points along a track section in a minimum of time, not exceeding that needed for.

simultaneously grading and tamping the track section if such additional track repair and/or maintenance operations are desired.

These and other objects are accomplished in accordance with this invention by laterally moving each track point in a path extending transversely of the track for a total distance constituting the sum of the distance by which the track point is spaced from a'desired position and a preferably constant, selected part of this distance, the track point being moved beyond the desired position by this additional part of the distance. The lateral movement causes track tension which results in a nearly predeterminable springback of the track, which is at least partly compensated by the additional part of the distance which the track point is moved.

The-distance of the springback along the transverse path in the opposite direction of the lateral movement is assumed to be in at least nearly constant proportion to the distance between the misaligned track point and its desired position. However, this proportion is not constant for all types of tracks and not even for each track section but varies in dependence on a number of factors. However, at any one operating time advantage that the additional part of the lateral moving distance, which is held at a constant proportion of the distance between the misaligned point and the desired position in a given track section, can be empirically determined in each section in dependence on local conditions and this proportion may be varied as these conditions change and produce a different track springback necessitating a different proportion of the additional lateral moving distance to the basic distance between the misaligned point and the desired position.

It has been found that the additional lateral moving distance is best determined when the track has been laterally moved to, and is held in, the desired position by the track lining unit. Of course, it will not always be possible to predetermine the distance of the track springback accurately, and thus properly to gage the additional lateral moving distance. If this cannot be done, the track point is successively laterally moved several times. The track point springs back after each lateral movement to a distance from the desired position which is smaller than the preceding distance of the track point from the desired position. The track point is laterally moved each time for a total distance constituting the sum of the smaller. distance, and the lateral movements are repeated until the smaller distance is at least substantially equal to'the distance of the springback whereby the track point is finally in the desired position.

The control system for making the additional distance for movement of the track beyond the desired position automatically proportional to the distance from the misaligned point to the desired position may take a number of forms.

In accordance with a preferred embodiment of the invention, this control system is responsive to the control means 'between a reference system and the motor means for laterally moving a track aligning unit engaged with the track rails, the control means operating the motor means at least until the track has been moved by the track lining unit for a distance along a path extending transversely of the track from a misaligned to a desired position. In response to the control means, the control system permits the same to continue operation of the motor means for moving the track laterally for an additional distance made proportional to the first-named distance by the control system. Such an automatic time-delay control can be readily constructed of sturdy parts and provided very accurate lining results.

With the method and apparatus of the present invention, it is possible to line a track section while the liner continuously progresses along the track without stopping at each track lining point. This can be accomplished with a liner incorporating two successive track lining units, wherein a first or front unit effectuates a first lateral movement of the track and any error in the lining is corrected by a second unit as it passes by the initially lined track point. Thus, the successive correction of the lining at any one point is effectuated by successive track lining units in a continuous lining operation by a continuously moving track liner although such a plurality of lining units may also be advantageously used in an intermittently proceeding operation.

BRIEF DESCRIPTION OF DRAWING The above and other objects, advantages and features of the present invention will become more fully understood by reference to the following detailed description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawing wherein:

FIGS. 1 to 4 are diagrams explaining graphically the principles underlying the method of this invention;

FIG. 5 is a schematic illustration, including a circuit diagram, of a control system useful in controlling the operation of the track lining units according to the invention; and

FIGS. 6 and 8 are schematic side views of two embodiments of track liners useful in practicing the method of the invention, FIG. 7 being a top view of FIG. 6.

DETAILED DESCRIPTION In the chart of FIG. 1, the zero line 0 shows the desired posi tion of the track center line while the line G indicates the actual position of the center line which is to be corrected by lining the track, i.e. moving the track laterally and perpendicularly to the center line at spaced correction points R-S. As is known in modern track lining, a lining machine moves on the track intermittently from correction point to correction point in the direction of track elongation, stopping at each correction point and laterally moving the lining unit at each point while the lining unit engages the track and thus moves the same laterally with the unit.

At each correction point, the misaligned track point S is first moved laterally beyond the desired position of the zero line to the reciprocally misaligned track point R in a path perpendicular to the zero line. Due to the inherent resilience of the track rails, the track springs back along this path either into the desired position of the center line or into another misaligned position. Thus, in the correction path of the track at each correction point, which extends perpendicularly to the center line of the track, the track lining units engaging the track rails move back and forth once'or several times before the desired track position is attained.

The chart of FIG. 2 shows in full line the line G indicating the actual track position as it deviates from the desired position of the track indicated by the zero line 0, deviations of the actual from the desired track position at different points of the track being indicated by distances x and y. The broken line R indicates how far beyond the desired track position the track must be laterally moved at each correction point to compensate for the resilient snapback of the track into the desired position. In the illustrated example, it has been assumed that this resilient snapback of the track amounts to about 0.25 times the distance x or y from the desired position, i.e. that the track must be laterally moved about one-quarter of such distance beyond the desired position to permit it to springback to the desired position.

The lateral oscillating movement in a path perpendicular to the center line of the track at each correction point of the track is not visible in the charts of FIGS. 1 and 2, and these movements have been graphically shown in FIGS. 3 and 4 which show the movements at each correction point in graphs ment 5 and a forked electric probe 6 having two electrical contacts on either side of reference chord 7 the contact of the chord with either of the contacts or the lack thereof indicating the lateral-track position in a manner fully disclosed, for instance, in our U.S. Pat. No. 3,314,373.

The hydraulic motors 4 consist .of a cylinden divided into two chambers by a piston gliding in thewcylinder and: connected to the lining rollers. The respective cylinder chambers receive hydraulic fluid from a pump P throughhydraulic'fluid feed lines 8,'8', the piston and the lining rollersfconnected thereto moving laterally in one or the other direction, depending on which cylinder chamber is supplied with hydraulic fluid. .A solenoid valve 8 is mounted between the pump P and the feed lines for the hydraulic motors to control the supply of hydraulic fluid thereto. The valve openingand closing is electrically controlled, an electrical control circuit-6 connecting the contacts of the chord probe 6 with the solenoid valve 8. This control circuit keeps the valve open to a selected feed line 8 and thus permits hydraulic fluid tofflow to the hydraulic motors at least until the lack of contact between reference line 7 and the contactsof probe 6 indicatesthatthe track is in the desired position in respect of the reference line.v

which expand each plane of correction in the direction of track elongation.

Referring first to FIG. 3, the misaligned track point S, is shown to be spaced from the desired zero line 0 by a distance x. It is ,moved laterally beyond the desired line by the same distance x to misaligned point R Due to the inherent resiliency of the track rails, it springs back to misaligned point S, which is spaced from the desired line by distance y. The

track must, therefore, again be laterally moved beyond the zero line by the same distance y to misaligned point R, whence it springs back to misaligned point 8;, where it is spaced from the zero line by distance z. It is then further moved laterally beyond the zero line by the distance -z to misaligned point R whence it finally snaps back to the desired zero line if this distance is equal to the snapback of the track. Thus, accurate lining at the point illustrated in FIG. 3 is accomplished only after the track has been laterally moved three times.

FIG. 4 illustrates this track oscillation perpendicularly to the center line of the track at a track lining point when the track snapback distance is shorter than the lateral movement of the track by the lining units. In this case, too, the misaligned track point S is spaced from the desired zero line 0 by a distance'x and is laterally moved beyond the desired line by the same distance x to misaligned point R However, the snapback distance of the track at this point is smaller than the distance x so that the misaligned point S has a distance y from the zero line on that side of the center line towards which the track was laterally moved. The track must now be laterally moved in the opposite direction to misaligned point R spaced by distance y from the zero line. This distance is about equal to the snapback distance in the chosen example so that the track will now be in the desired alignment at this point.

In the examples of FIGS. 3 and 4, the track was laterally moved beyond the desired position of the center line by the same distance by which the particular track point was spaced from the desired position, i.e. the lateral moving distance was multiplied by the constant k=l to arrive at the probably distance of snapback. In actual operations, the constant k will be empirically determined.

A control system for practicing the method of the present invention is shown in FIG. 5.

A track liner (not shown in this FIG.) moves on a track consisting of rails l resting on ties 2. Track lining units are mounted on the liner, each unit including flanged lining rollers 3 for engagement with a rail 1 and hydraulic motors 4 for moving the rollers laterally and perpendicularly to the rail, thus moving the rail in the same direction when the lining rollers engage the rail. The lateral movement of the lining units is ob served and controlled by sa system including a rail sensing ele- An additional solenoid valve 9 is'arranged in each hydraulic fluid feed line 8 and provides an additional control for the duration of the operation of the hydraulic motors 4. The valve 9 is used to extend the operation of themotors to a controllable extent. Valve 9 is actuated by a time-delay system l0'l5 in the following manner: i 1

While the valve'8 connects the pump P with a selected feed line 8' to operate the hydraulic motors 4, a branch line 8"! supplies hydraulic fluid to one of the chambers of cylinder 11 through throttle valve 10,. Piston 12 in cylinder 11 moves in I the direction of the arrow under the pressure of the hydraulic fluid flowing into the cylinder chamber. A slide 14 is coupled to piston 12 for movement therewith, this slide successively operating a series ofmicroswitches 13 arranged in-the path of the movement of the slide. The microswitches are associated with a series of time-delay relays ISQDepending on the dura-' tion of the operation of the hydraulic motors 4, i.e. the period during which valve 8 is kept open by electric'control circuit 6',

which in turn depends on the distance of the lateral track movement determined by reference line 7, the slide 14 selects and operates that time-delay relay 15 whose time-delay has a predetermined ratio to the duration, i.e. distance, of the' lateral track movement, which ratio is variably selectable but is kept at least substantially constant in any given track section to be lined. The time-delay relay 15 selected and operated by slide 14 delays the closing of valve 9 sufficiently to permit;

operation of the hydraulic motors beyond the point'determined by reference line 7, i.e. beyond the desired position of the track. The time delay is so selected that this additional movement corresponds at least roughly to the expected springback of the track at the lining point. The valve 8 is so coupled with valve 9 that it is closed only when the predetermined time delay has ended.

FIGS. 6 to 8 show different embodiments of otherwise conventional mobile track liners which may be used in practicing the present invention.

The mobile track liner of FIGS. 6 and 7 comprises a frame 20 mounted on running gears 24, 25. The track lining units 21 are mounted on the frame centrally between the running gears. This liner works with two reference lines l7, 17' which may consist of rods or wires. The reference line 17' extends.

over a track section to be lined as the liner moves in the direction of the arrow shown in full lines, one end of the line being anchored to buggy 15' while the other line end is anchored to buggy 22, the lining units 21 being located between the two line ends. The other reference line 17 extends from the buggy 22 to a buggy 15, being anchored in fixed relation to the track to a buggy 23 at a point inter- I mediate its ends. As shown by the arrow in broken line, the liner may be operated in either direction along the track. j When its operating direction is reversed, the rear reference line 17' is fixedly held in relation to the track at buggy 23' intermediate its ends and extends between buggies l5 and 22. In this case, the front reference line extends from buggy 22 to buggy 15, with thelining units arranged intermediate its ends. The buggies l5, are coupled to'frame by preferably telescoping spacing rods, as is well known.

FIG. 8 illustrates a mobile track tamper useful for grading and lining track. It comprises a frame mounted on running gears 24', 25' and a forward frame portion overhanging the front running gear 24 and holding a vertically adjustable carrier (not shown) for tamping tools 31, as shown, for instance, in our US. Pat. No. 2,915,018. The front end of the overhanging frame portion carries a hydraulic motor 33 connected to.

the rail engaging roller assembly 33 andoperable to move this assembly upwardly and/or laterally so that the track rails engaged by the rollers of the assembly may be moved in the same direction for grading and/or lining the track at this point. For grading, the piston is moved in the cylinder of the hydraulic motor to lift the assembly. The hydraulic motor itself may be mounted for lateral movement in a bearing extending transversely of the track on the front end of the overhanging frame portion so that lateral movement of the motor may laterally move the track engaged by the rail engaging rollers of the assembly. In the illustrated embodiment, a further track lining unit 21 is mounted on the frame between the running gears. The two lining units 33 and 21' enable this machine to line the track simultaneously at several points or to line the same point twice in succession. This enables a continuously progressing lining operation to be effected, the front lining unit 33 imparting a first lateral movement to the track and any remaining correction being effected subsequently by the rearward lining unit 21'.

The reference system used in controlling the lining opera-' tion again includes two reference lines 27 and 27 extending from front buggy 25' to rear buggy 25, the rear buggy being coupled tothe frame by a spacing rod. Furthermore, since the machine is also used for grading, an additional reference system controlling the grading operation is also provided. This additional reference system includes a reference line 34 which is shown as a beam emitted from sender 35 mounted on front buggy 25' to receiver 36 mounted on the previously corrected section of track rails l by a support rod behind the rail engaging assembly 32, 33 and tampers 31. An indicating element 37, such as a stop, is also mounted on a rod on the track rails in the region of the track correction point, and when the desired grade has been reached and the indicating element has been correspondingly lifted with the track, the stop will interrupt the beam and thus cause the grading operation to cease in a manner well known.

While the invention has been described in connection with certain preferred embodiments, it will be understood that many variations and modifications of structural details will reference system determining said distance whereby the track is moved from a misaligned into a desired position, control means between the reference system and the motor means for operating the motor means at least until the track has been moved by the track lining unit for said distance, and a control system responsive to the control means and permitting said control means to continue operation of the motor means for moving the track laterally for an additional distance made proportional to the first-named distance by the control system.

2. The track liner of claim 1, wherein the control system includes a plurality of devices operational to make the additional distance proportional to different lengths of said firstnamed distance. I

3. The track liner of claim 1, wherein the control system includes a time-delay device for continuing operation of the motor means for moving the track laterally for said additional distance.

4. The track liner of claim 1, comprising a second track lining unit spaced from the first-named unit in the direction of elongation of the track, the first-named unit being operable to move the track laterally for a total distance taking into consideration the springback of the track due to track tension after the lateral movement, and the second track lining unit occur to those skilled in the art without departing from the being operable formoving the track laterally for a distance sufficient to provide accurate lining.

5. A track liner comprising a frame mounted for mobility on the track rails, a track lining unit mounted on the frame for engagement with the track rails, motor means for laterally moving the track lining unit engaged with the track rails for a distance along a path extending transversely of the track, a reference system determining said distance whereby the track is moved from a misaligned into a desired position, control means betweenthe reference system and the motor means for operating the motor means at least until the track has been moved by the track lining unit for said distance, and a control system responsive to the control means and permitting said control means to continue operation of the motor means for moving the track laterally for an additional distance made proportional to the first-named distance by the control system, the control system including a plurality of time-delay devices for continuing operation of the motor means for moving the track laterally for said additional distance, each time-delay device including a time-delay relay set to produce a different length of said additional distance proportional to a different length of said fii'st-named distance, and said control system further comprising means for selecting one of said time-delay relays in response to said control means.

6. The track liner of claim 5, wherein the motor means is hydraulically operated, the control means includes a hydraulic fluid feed line means to the motor means and valve means for discontinuing hydraulic fluid flow through said feed line means to the motor means, and a drive means is coupled to the relay selecting means, the drive means being actuated in response to the movement of the track lining unit.

7. The track liner of claim 6, wherein said drive means is a hydraulic motor, a branch hydraulic fluid feed line delivering hydraulic fluid to said hydraulic motor when the hydraulic fluid fluid feed line means delivers hydraulic fluid to the motor means. 

1. A track liner comprising a frame mounted for mobility on the track rails, a track lining unit mounted on the frame for engagement with the track rails, motor means for laterally moving the track lining unit engaged with the track rails for a distance along a path extending transversely of the track, a reference system determining said distance whereby the track is moved from a misaligned into a desired position, control means between the reference system and the motor means for operating the motor means at least until the track has been moved by the track lining unit for said distance, and a control system responsive to the control means and permitting said control means to continue operation of the motor means for moving the track laterally for an additional distance made proportional to the first-named distance by the control system.
 2. The track liner of claim 1, wherein the control system includes a plurality of devices operational to make the additional distance proportional to different lengths of said first-named distance.
 3. The track liner of claim 1, wherein the control system includes a time-delay device for continuing operation of the motor means for moving the track laterally for said additional distance.
 4. The track liner of claim 1, comprising a second track lining unit spaced from the first-named unit in the direction of elongation of the track, the first-named unit being operable to move the track laterally for a total distance taking into consideration the springback of the track due to track tension after the lateral movement, and the second track lining unit being operable for moving the track laterally for a distance sufficient to provide accurate lining.
 5. A track liner comprising a frame mounted for mobility on the track rails, a track lining unit mounted on the frame for engagement with the track rails, motor means for laterally moving the track lining unit engaged with the track rails for a distance along a path extending transversely of the track, a reference system determining said distance whereby the track is moved from a misaligned into a desired position, control means between the reference system and the motor means for operating the motor means at least until the track has been moved by the track lining unit for said distance, and a control system responsive to the control means and permitting said control means to continue operation of the motor means for moving the track laterally for an additional distance made proportional to the first-named distance by the control system, the control system including a plurality of time-delay devices for continuing operation of the motor means for moving the track laterally for said additional distance, each time-delay device including a time-delay relay set to produce a different length of said additional distance proportional to a different length of said first-named distance, and said control system further comprising means for selecting one of said time-delay relays in response to said control means.
 6. The track Liner of claim 5, wherein the motor means is hydraulically operated, the control means includes a hydraulic fluid feed line means to the motor means and valve means for discontinuing hydraulic fluid flow through said feed line means to the motor means, and a drive means is coupled to the relay selecting means, the drive means being actuated in response to the movement of the track lining unit.
 7. The track liner of claim 6, wherein said drive means is a hydraulic motor, a branch hydraulic fluid feed line delivering hydraulic fluid to said hydraulic motor when the hydraulic fluid fluid feed line means delivers hydraulic fluid to the motor means. 